odhcp6c - Embedded DHCPv6 Client

Abstract

odhcp6c is a minimal DHCPv6 and RA-client for use in embedded Linux systems especially routers. It compiles to only about 35 KB (-Os -s).

Features

1. IPv6 bootstrap from different environments with autodetection a) RA only b) RA + stateless DHCPv6 c) RA + stateful DHCPv6 (either IA_NA or IA_PD or both)

2. Handling of non-temporary addresses (IA_NA) a) handling of valid and preferred lifetimes b) automatic fallback to stateless or PD-only mode

3. Support for DHCPv6 extension a) Reconfigure-Messages b) Prefix Delegation (including handling of valid and preferred lifetimes) c) Prefix Exclusion d) DNS Configuration Options e) NTP Options f) SIP Options g) Information-Refresh Options h) Configurable SOL_MAX_RT i) DS-Lite AFTR-Name Option j) Softwire address and port mapped clients (MAP, LW4over6) j) CER-ID (experimental) k) Server unicast Option

4. Support for requesting and parsing Router Advertisements a) parsing of prefixes, routes, MTU and RDNSS options

Compiling

odhcp6c uses cmake:

• To prepare a Makefile use: "cmake ."
• To build / install use: "make" / "make install" afterwards.
• To build DEB or RPM packages use: "make package" afterwards.

State Script

The state script is called whenever the DHCPv6 state changes. The script is called with the following parameters:

States:

• started The DHCPv6 client has been started
• bound A suitable server was found and addresses or prefixes acquired
• informed A stateless information request returned updated information
• updated Updated information was received from the DHCPv6 server
• ra-updated Updated information was received from via Router Advertisement
• rebound The DHCPv6 client switched to another server
• unbound The DHCPv6 client lost all DHCPv6 servers and will restart
• stopped The DHCPv6 client has been stopped

Environment:

• RDNSS A space-separated list of recursive DNS servers
• DOMAINS A space-separated list of DNS search domains
• SNTP_IP A space-separated list of SNTP server IP addresses
• SNTP_FQDN A space-separated list of SNTP server FQDNs
• SIP_IP A space-separated list of SIP servers
• SIP_DOMAIN A space-separated list of SIP domains
• OPTION_ Custom option received as base-16
• PREFIXES A space-separated list of prefixes currently assigned Format: /,preferred,valid[,excluded=/][,class=<prefix class #>]
• ADDRESSES A space-separated list of addresses currently assigned Format:
  /,preferred,valid
• RA_ADDRESSES A space-separated list of addresses from RA-prefixes Format:
  /,preferred,valid
• RA_ROUTES A space-separated list of routes from the RA Format:
  /,gateway,valid,metric
• RA_DNS A space-separated list of recursive DNS servers from the RA
• RA_DOMAINS A space-separated list of DNS search domains from the RA
• RA_HOPLIMIT Highest hop-limit received in RAs
• RA_MTU MTU-value received in RA
• RA_REACHABLE ND Reachability time
• RA_RETRANSMIT ND Retransmit time
• AFTR The DS-Lite AFTR domain name
• MAPE / MAPT / LW4O6 Softwire rules for MAPE, MAPT and LW4O6